Concepcion, 19, defected from Cuba in the Netherlands after being named rookie of the year for the Cuban national team. He will be invited to spring training, but is not expected to make the rotation. The Tribune first reported the team's interest in him during December's winter meetings.

"I would not throw him into the major leagues yet," agent Jaime Torres said. "While I think he can make it really fast, he is only 19. But this kid has good stuff, a great makeup and he's extremely intelligent."

Concepcion's fastball, according to scouts, is about 92 mph, but he has an exceptional curveball and very good changeup.

Among the Cubs' competitors for Concepcion were the White Sox, although he was believed to have preferred the Cubs weeks ago.The Cubs and Sox remain active in bidding for Cuban outfielders Yoenis Cespedes and Jorge Soler.